1. Field
This disclosure relates generally to charge pumps, and more specifically, to variable input voltage charge pumps.
2. Related Art
With the proliferation of battery powered products in medical, consumer and industrial applications the variety of power supply voltages available for integrated circuits has increased. In previous products the power supply voltages have generally been greater than or equal to the integrated circuit's supply voltage requirement. Recently, however, in many battery-powered applications the product supply voltage may at one time be greater than the supply voltage required by the integrated circuit and at another time be less than the required supply voltage. As a consequence, the need for circuits that can change a range of voltages to the well-regulated voltage required by an integrated circuit has increased. These circuits must address a number of design challenges.